Why a Taiwan Invasion Would Look Nothing Like D-Day (2023)

Every year on June 6, the United States and its NATO allies commemorate the anniversary of D-Day, the daring amphibious assault on France’s Normandy region that helped bring down Nazism and liberated Western Europe. Today, commentators frequently draw parallels between D-Day and an imagined Chinese invasion of Taiwan. But such comparisons are wrong. Here’s why.

Emotion Versus Logic

Most observers view the Normandy landings as a glorious moment in human history. The very thought of D-Day evokes strong positive emotions, especially for citizens in the Western democracies that were involved. It’s easy to see, then, why likening D-Day to the invasion of democratic Taiwan could be problematic. Chinese Communist Party (CCP) propaganda notwithstanding, Beijing’s campaign would be about spreading tyranny, not liberating oppressed peoples.

That’s why I like to use the term Zero Day (Z-Day) to refer to the notional date of a future Chinese invasion of Taiwan. Z-Day is the term Winston Churchill used when talking about a potential Nazi invasion of England, an operation Adolf Hitler planned to launch in 1940, but aborted after he lost the battle for air supremacy over the English Channel. While all historical metaphors are imperfect, this one seems fitting, even hopeful. For England, Z-Day never actually arrived.

But if a future Z-Day did come to Taiwan’s shores, it wouldn’t be like the Normandy landings. Our natural impulse when thinking about future amphibious operations is to look to the past. Yet the reality of this scenario is that no good point of comparison exists. Nothing even remotely similar has occurred in history.

Contrasts Galore

It’s easy to forget that World War II’s grandest amphibious operation was actually a relatively simple affair in terms of the battlespace. The D-Day landings occurred in rural France along a relatively flat, 80-kilometer beachfront. The harrowing bluffs overlooking Omaha Beach made famous by the Hollywood movie “Saving Private Ryan” were only between 100 and 170 feet high. Few civilians lived in the area, which had been extensively bombed prior to the assaults.

Normandy’s beaches were heavily fortified, but lightly garrisoned. They were defended by around 50,000 troops under German command. To defeat them, the Allies employed over 6,000 ships and over 1,000 aircraft, which together landed approximately 155,000 troops on D-Day, including 24,000 by air.

Now think of a very different battlefield. Taiwan is a rugged, heavily urbanized nation of 23.6 million people. The country of Taiwan (also known as the Republic of China) is made up of over 100 islands, most too tiny to see on the map. Many of Taiwan’s outer islands bristle with missiles, rockets, and artillery guns. Their granite hills have been honeycombed with tunnels and bunker systems.

The main island of Taiwan is 394 kilometers long and 144 kilometers across at its widest point. It has 258 peaks over 3,000 meters in elevation. The tallest, Yushan, or “Jade Mountain,” is just under 4,000 meters high.

Unlike Normandy, the coastal terrain here is a defender’s dream come true. Taiwan has only 14 small invasion beaches, and they are bordered by cliffs and urban jungles. Linkou Beach near Taipei provides an illustrative example. Towering directly over the beach is Guanyin Mountain (615 meters). On its right flank is the Linkou Plateau (250 meters), and to its left is Yangming Mountain (1,094 meters). Structures made of steel-reinforced concrete blanket the surrounding valleys. Taiwan gets hits by typhoons and earthquakes all the time, so each building and bridge is designed to withstand severe buffeting.

This extreme geography is densely garrisoned by armed defenders. In wartime, Taiwan could mobilize a counter-invasion force of at least 450,000 troops, and probably far more. While Taiwan’s standing military is only around 190,000 strong, it has a large reserve force comprised primarily of recent conscripts with basic training. In 2020, Taiwan’s then defense minister estimated that 260,000 reservists could be mobilized in a worst-case scenario to augment active-duty personnel. This appears to be a conservative estimate.

Over 2 million young Taiwanese men are in the military’s reserve system, along with a large number of registered government personnel and contractors. Taiwan’s all-out defense strategy encompasses police officers, firefighters, airline personnel, bulldozer operators, construction workers, truck drivers, bus drivers, fishing boat crews, doctors, nurses, and many others. By law, pretty much anyone with a useful wartime skill could be pressed into national service.

Unknowns

It is not public information how many guns Taiwan has stockpiled for its army, marine, and military police reservists. Nor is it clear whether Taiwan’s unpopular and poorly-resourced reserve system could effectively mobilize and use a significant number of them. Much would depend on early warning intelligence, and the will of Taiwan’s president and her cabinet to act with alacrity. Democracies are often reluctant to declare national emergencies and institute martial law until the enemy invasion starts. This might be why the former defense minister pessimistically assumed he would only be able to mobilize around 15 percent of the military’s total reserve force.

Were it to occur, the battle for Taiwan would involve other complexities that are vital but squishy, meaning they cannot be satisfactorily quantified. It would be the first country-on-country war where both attacker and defender had modern, long range missiles in their arsenals capable of cracking open ships and devastating land targets with precision from hundreds of kilometers away. No one actually knows what such a fight would look like because it’s never happened before.

Both sides would have advanced cyber weapons, electronic warfare suites, smart mines, and drone swarms that have never been tested in real-world combat. Both would have satellites and at least some ability to attack satellites. Both would have economic leverage to use and the ability to cripple the other’s economy.

Both would have large numbers of its citizens living in the other’s territory, a certain but unknown number of whom are saboteurs and spies (and some of those double agents). Both would have the fearful option of using weapons of mass destruction to disperse biological, chemical, and radioactive agents against the other. And both might apply more exotic weapons, such as directed energy weapons and hypersonic missiles.

The most critical question, of course, is what the United States would do. It seems logical to assume the White House would send aid to Taiwan. Whether or not the president would order U.S. forces to defend Taiwan is currently unknown. Nonetheless, according to the Taiwan Relations Act, the U.S. military must plan on defending Taiwan and prepare accordingly.

Unlike the U.S. military, the PLA has not seen combat since 1979. As a result, nobody serving today in China has any combat experience except for a handful of geriatric generals.Equally important, the Chinese military does not train in realistic, highly complex environments.These two facts call into question whether or not the PLA could actually pull off a complex invasion operation successfully.If the U.S. came to Taiwan’s defense, few experts would give China good odds.

Number Crunching

Some things we can count on, or at least estimate with the help of computers. The quantifiable elements of the PLA invasion operation would be mindboggling. Millions of armed forces in uniform would be mobilized in China, including soldiers, sailors, airmen, rocketeers, marines, cyber warriors, armed police, reservists, ground militia, and maritime militia. It seems likely that somewhere between 1 and 2 million combat troops would actually have to cross the Taiwan Strait, which is 128 kilometers across at its narrowest point and 410 kilometers at its widest opening.

PLA troop numbers, of course, are highly speculative “best” guesses, which depend entirely on assumptions. In theory, the PLA might land as few as 300,000 to 400,000 soldiers, for example if the Taiwanese president was killed or captured prior to Z-Day and armed resistance crumbled. On the other hand, if the Taiwanese government survived and mobilized everything under its power in a timely fashion, the PLA might have to send over 2 million troops to Taiwan, including paramilitaries such as the People’s Armed Police and the Militia of China.

Why so many? Commanders planning offensive operations typically want a 3-to-1 superiority over the defender. If the terrain is unfavorable, they might want a 5-to-1 ratio (and sometimes more). Assuming Taiwan had 450,000 defenders, the PLA general in charge would therefore want to have at least 1.35 million men, but probably more like 2.25 million. Obviously, this is a simplistic formula. But without access to top secret Chinese military studies and plans, a logical estimate is better than the alternative.

If the PLA ground force was a million or more men, then we might expect an armada of thousands or even tens of thousands of ships to deliver them. The vast majority of these ships would not be from the PLA Navy. Vessels like tugs, oilers, barges, ferries, fishing boats, semi-submersible platforms, container carriers, and heavy roll-on/roll-off cargo ships would be mobilized. According to Chinese military doctrine, many ships would be deployed as decoys, conducting feints to distract attention away from the main assault.

For the PLA, enormous ship numbers are now attainable. The CCP’s military-civil fusion strategy has been gearing up for just such an operation. China’s civilian fleets are vast, and every day more hulls are being retrofitted to support a future military campaign against Taiwan.

For Beijing to have reasonable prospects of victory, the PLA would have to move thousands of tanks, artillery guns, armored personnel vehicles, and rocket launchers across with the troops. Mountains of equipment and lakes of fuel would have to cross with them. In addition to ships, thousands of transport planes and helicopters would be involved in the mammoth lift operation.

Over 90 million CCP members would be supporting the war effort, along with the industrial might of a nation of 1.3 billion people. China’s Marxist-Leninist system is uniquely capable of extracting private resources for the state’s use. According to Xi Jinping, one of the CCP’s greatest strengths is its ability to force collective action and conduct mass campaigns, especially in times of emergency.

The invasion of Taiwan would be the supreme emergency for all sides. It would be unlike anything ever seen before. It would new, different, and unpredictable.

Preserving Peace

Much is unknowable and nothing is inevitable about a potential Chinese invasion of Taiwan. The complexities inherent in this scenario are impossible to account for with a high degree of confidence. Even war games played on the Pentagon’s supercomputers rely on hefty inputs of human guesswork. A lot of it is pure wind. That’s the point. Wargame designers want military officers to experience defeat and talk over problems so they can do better in the real world. These are training exercises, not visits to some digital Oracle of Delphi.

Our minds are naturally drawn toward binaries, simple black and white formulas that help us make sense of the world. Consider these statements: “Beware! Z-Day is coming soon.” “Chill the hype! Z-Day will never come.” “Surrender! Taiwan is indefensible.” “Relax! Taiwan is impregnable.”

These are all false choices. The truth is that the future is unseeable; no one knows what it might bring. Sometimes the more we study something that is truly complex, the less sure we are that we understand it. And sometimes that’s a good thing.

If he is sane, Xi Jinping will think hard before ordering an attack on Taiwan and realize how quickly events could spin out of his control. But can we really trust a dictator who stands accused of genocide to act in a rational manner? That seems unwise.

There are countless things the United States and Taiwan can do in the open to raise doubts in Xi’s mind. There are even more things they can do in secret to prepare to win on Z-Day if that becomes necessary. Washington and Taipei have their work cut out for them.

The United States and Taiwan should strive toward what my colleague Mark Stokes has a dubbed a NSC (normal, stable, and constructive) relationship. The current ambiguity surrounding Washington’s policy toward Taiwan is destabilizing because it isolates Taipei, emboldens Beijing, and invites miscalculation on all sides.

Preserving peace for the long haul will require fresh thinking, political willpower, and a greater sense of vigilance. A basic knowledge of geography − and history − might also help.